import 'dart:convert';

import 'package:flutter/material.dart';


void main() {
  runApp(const MaterialApp(home: _SecondScreen()));
}

class _SecondScreen extends StatelessWidget {
  const _SecondScreen({super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Second Screen'),
      ),
      body: const _A()
    );
  }
}

class  _A  extends  StatelessWidget{
  const _A({super.key});

  @override
  Widget build(BuildContext context) {
   return Center(
      child: Container(
        width: 200,
        height: 200,
        decoration: BoxDecoration(
          border: Border.all(
            color: Colors.blue.withOpacity(0.3), // 边框颜色
            width: 1,           // 边框宽度
            style: BorderStyle.solid, // 边框样式：实线，其他选项还包括 dashed (虚线) 或 dotted (点线)
          ),
          borderRadius: BorderRadius.circular(16), // 圆角半径
        ),
        child: const Center(
          child: Text('Hello, World!'),
        ),
      ),
    );
  }


}
